There was a healthy amount of change between last week and this week in the RPI rankings released by the Iowa High School Athletic Association. And it’s made Week 9 of the 2018 football season all the more intriguing.

District titles are still up for grabs, and the remaining teams are all jockeying for wild-card positioning. The association announced this week that all playoff qualifiers will be announced around midnight following Friday's games. The brackets will be released sometime early on Saturday morning, probably between 2-3 a.m.

Remember: All district champs (including ties) earn automatic playoff berths. There are still tiebreaker procedures that exist for determining which of the tied teams would be first eligible to host a playoff game.

The RPI formula is three parts: a team’s overall win-loss record, accounting for 37.5 percent; a team’s opponents’ win-loss record, also accounting for 37.5 percent; and a team’s opponent’s opponents’ win-loss record, which accounts for the remaining 25 percent.

Here, we’ll list the top 16 teams, plus the next four and district leaders outside of the top 20, in each class as well as their respective RPI percentages. We’ve bolded the current district leaders so you know who is in line to earn automatic bids, and then offer some analysis underneath each poll:

CLASS 4A

Ankeny Centennial, 8-0 — .6941 (District 2)

West Des Moines Valley, 8-0 — .6831 (District 7)

Cedar Falls, 8-0 — .6829 (District 3)

Iowa City West, 7-1 — .6582 (District 4)

Bettendorf, 7-1 — .6518 (District 5)

Johnston, 7-1 — .6483 (District 6)

Cedar Rapids Prairie, 7-1 — .6408 (District 3)

Dowling Catholic, 6-2 — .6331 (District 1)

Waukee, 6-2 — .6308 (District 6)

Fort Dodge, 6-2 — .5968

Indianola, 6-2 — .5816

Pleasant Valley, 4-4 — .5556

Urbandale, 5-3 — .5509

Cedar Rapids Kennedy, 5-3 — .5478

Ames, 5-3 — .5446

Sioux City East, 5-3 — .5409

Next Four

Ankeny, 4-4 — .5322

Davenport North, 5-3 — .5289

Davenport Central, 4-4 — .5156

Southeast Polk, 3-5 — .5125

Analysis: Probably the class that makes the most sense, in that all the district leaders are on top. Keep an eye on Ankeny, who plays Sioux City East, and Southeast Polk, who plays Des Moines Roosevelt, to potentially make a move into those wild-card spots. Among the other Week 9 contests: Urbandale-Ames is essentially a play-in game, and Indianola, Pleasant Valley and Cedar Rapids Kennedy can likely secure at-large bids with victories, too.

CLASS 3A

Sergeant Bluff-Luton, 7-1 — .7224 (District 1)

Lewis Central, 8-0 — .6948 (District 9)

Cedar Rapids Xavier, 8-0 — .6933 (District 4)

Solon, 8-0 — .6836 (District 6)

North Scott, 7-1 — .6784 (District 5)

Bishop Heelan, 7-1 — .6672

Oskaloosa, 7-1 — .6570 (District 7)

Decorah, 6-2 — .6518 (District 3)

Waverly-Shell Rock, 7-1 — .6468

Clear Creek-Amana, 7-1 — .6464

Harlan, 6-2 — .6314

Pella, 7-1 — .6271

Spencer, 6-2 — .6202

Western Dubuque, 6-2 — .6165

Norwalk, 5-3 — .5698 (District 8)

Independence, 6-2 — .5648

Next Four

Washington, 5-3 — .5596

Storm Lake, 4-4 — .5530

ADM, Adel, 5-3 — .5511

Marion, 4-4 — .5415

District leaders not in top 20

Carroll, 5-3 overall, 4-0 in District 2, 25th in RPI (.5309)

Analysis: Carroll is in line to steal a playoff bid from someone in the top 16. The Independence-Decorah game this Friday will be big. An Independence win would muddy up Class 3A’s District 3. A Decorah win would clinch the district crown and likely ensure that Independence misses the playoffs. Teams such as Pella, Spencer and Western Dubuque also need wins to keep at-large bids alive.

Analysis: Class 2A remains wide-open. The current three-way tie in District 9 is interesting, considering that Greene County could beat OABCIG but still lose the potential of hosting a first-round game because of their loss to Carroll Kuemper in Week 6. There may be a team or two that finishes in the top 16 but gets left out of the playoffs because of where some district champs finish. We’ll see.

CLASS 1A

Bellevue, 8-0 — .6858 (District 4)

South Central Calhoun, 8-0 — .6829 (District 2)

Interstate 35, 8-0 — .6802 (District 7)

Van Meter, 8-0 — .6669 (District 8)

Pella Christian, 6-2 — .6649 (District 7)

West Branch, 7-1 — .6549

Dike-New Hartford, 8-0 — .6456 (District 6)

West Sioux, 7-1 — .6227 (District 1)

Wilton, 7-1 — .6209 (District 5)

Treynor, 7-1 — .6013 (District 9)

Osage, 6-2 — .5972 (District 3)

Mediapolis, 7-1 — .5858

West Lyon, 6-2 — .5802

Mount Ayr, 6-2 — .5731

Cascade, 5-3 — .5716

Underwood, 5-3 — .5664

Next Four

South Hamilton, 6-2 — .5627

Sumner-Fredericksburg, 6-2 — .5583

Sigourney-Keota, 5-3 — .5525

Iowa City Regina, 5-3 — .5521 (District 6)

Analysis: Iowa City Regina basically needs to beat Dike-New Hartford to make the playoffs — their game this Friday will decide the District 6 crown. Do that, and the Regals will steal a playoff bid from someone at the bottom of the poll. Speaking of which, the math could break so that South Hamilton, Sumner-Fredericksburg and/or Sigourney-Keota could overtake Mount Ayr, Cascade and/or Underwood. Week 9 will be interesting in Class 1A.

Southeast Polk Rams head coach Brad Zelenovich talks to his Rams during their game wit the Marshalltown Bobcats at SE Polk Stadium. The Rams beat the Bobcats 56 to 7. Reese Strickland / For the Register

Southeast Polk Rams Jr. High students having a good time at their football game against the Marshalltown Bobcats at SE Polk Stadium. The Rams beat the Bobcats 56 to 7. Reese Strickland / For the Register

West Branch football head coach Butch Pedersen embraces senior lineman Jaden Hierseman (52) before a Class A varsity football game on Friday, Oct. 12, 2018, at the Little Rose Bowl in West Branch, Iowa. Joseph Cress/Iowa City Press-Citizen

West Branch football head coach Butch Pedersen embraces senior lineman Drake Bloem (72) before a Class A varsity football game on Friday, Oct. 12, 2018, at the Little Rose Bowl in West Branch, Iowa. Joseph Cress/Iowa City Press-Citizen

West Branch's Beau Cornwell (3) rushes from the 1-yard-line for a touchdown during a Class A varsity football game on Friday, Oct. 12, 2018, at the Little Rose Bowl in West Branch, Iowa. Joseph Cress/Iowa City Press-Citizen

West Branch's Beau Cornwell (3) avoids tackles rushing during a Class A varsity football game on Friday, Oct. 12, 2018, at the Little Rose Bowl in West Branch, Iowa. Joseph Cress/Iowa City Press-Citizen

Cascade's Jackson Knepper (4) tackles West Branch's Tanner Lukavsky (32) during a Class A varsity football game on Friday, Oct. 12, 2018, at the Little Rose Bowl in West Branch, Iowa. Joseph Cress/Iowa City Press-Citizen

Cascade's Logan Otting (11) celebrates with Brett Bower (3) after catching a touchdown pass during a Class A varsity football game on Friday, Oct. 12, 2018, at the Little Rose Bowl in West Branch, Iowa. Joseph Cress/Iowa City Press-Citizen

Cascade's Haris Hoffman (5) gets tackled by West Branch's Tanner Lukavsky (32) during a Class A varsity football game on Friday, Oct. 12, 2018, at the Little Rose Bowl in West Branch, Iowa. Joseph Cress/Iowa City Press-Citizen

West Branch's Beau Cornwell (3) is embraced by Jaden Hierseman (52) after scoring a touchdown from the 1-yard-line during a Class A varsity football game on Friday, Oct. 12, 2018, at the Little Rose Bowl in West Branch, Iowa. Joseph Cress/Iowa City Press-Citizen

Valley's Jack Johnson (8) cant come up with the pass during their football game against Ames at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Valley's Creighton Mitchell (9) rushes during their football game against Ames at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Valley's Creighton Mitchell (9) rushes during their football game against Ames at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Valley football coach Gary Swenson talks to an official during their football game against Ames at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Valley's Avry Bonacci (33) prays before their football game against Ames at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Valley's Nate Willcockson (45) runs in to the endzone during their football game against Ames at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Ames' Will Krapfl (2) can't reach a pass during their football game against Valley at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Valley's Beau Lombardi (12) looks for a pass during their football game at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Valley's Roy Jensen (5) intercepts a pass after it was tipped by Valley's Jon Shaner (22) during their football game against Ames at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Valley's Roy Jensen (5) intercepts a pass after it was tipped by Valley's Jon Shaner (22) during their football game against Ames at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Valley's Tre Fugate (7) jumps into the endzone for a touchdown during their football game against Ames at Valley Stadium on Friday, Oct. 12, 2018, in West Des Moines. Valley takes a 31-0 lead into halftime. Brian Powers/The Register

Analysis: Some intriguing situations in Class A. South O’Brien needs to beat Hinton and hope Akron-Westfield loses to MMCRU to reach the playoffs. St. Albert needs to beat AHSTW to make the field. Even more, Lynnville-Sully and Mason City Newman are in line to potentially steal bids from the at-large field, unless other teams lose. A couple of good teams will probably get left out.

Analysis: Lots of intriguing Week 9 matchups will affect the 8-Player playoff race. The RPI may have to decide the first-round host from District 3, because Midland beat Central City, who beat Turkey Valley, who beat Midland. Gladbrook-Reinbeck is in line to steal a playoff spot from the at-large pool. Stanton plays Fremont-Mills in Week 9, and a win will secure a playoff spot.

Cody Goodwin covers wrestling and high school sports for the Des Moines Register. Follow him on Twitter at @codygoodwin.